1. Field of the Invention
The present invention is directed to a stock material from which air turning vanes may be formed, and to an air guide assembly formed therefrom, such assembly being used in air conduits such as air conditioning and heating ducts.
2. The Prior Art
It is conventional in order to increase the flow efficiency of air moving in the air ducts of air heating and cooling installations to provide air guides at the bends or corners.
In accordance with U.S. Pats. No. 2861,597 of Nov. 25, 1958 and No. 2959,195 of Nov. 8, 1960, the air guides may be comprised of a spaced pair of parallel rails. The rails may include paired projections having slots converging toward the center line of the rails. Arcuate sheet metal scoops or vanes extend between the spaced rails, the transverse edges of the rails extending into the slots of the protuberances and being secured therein to define a three dimensional structure.
The structure is mounted in the corner or bend area of a duct and minimizes turbulent flow so as to increase the efficiency with which air moves in the ducting.
The vane members which extend between the rails have heretofore been supplied as precurved elongate sheet metal elements from which increments are cut in accordance with the spacing of the rails, which spacing is, in turn, dictated by the transverse dimension of the duct.
The use of stock vane materials of the type described is economically undesirable both from the standpoint of wastage of material and from the standpoint of efficiency of air conduction.
By way of example, where the vane material is supplied in eight foot lengths and a vane length of one and one half feet is required, it will be evident that portions of the eight foot length must be discarded
Similarly, from the flow efficiency standpoint, it is desirable that the entry and exit edges of the vane will run parallel to the input and output axes of the duct.
While stock material thus may be prebent to conduct air about a 90.degree. turn, leaving the entry and exit edges of the vane material parallel to the input and output duct axes, such vane material will exhibit less than optimal flow and guidance characteristics where installed at a duct bend of less than 90.degree..
Obviously it is impracticable to supply precurved lengths of duct material adapted to accommodate each and every angular bend within a ducting system.
U.S. Pat. No. 2972,358 of Feb. 21, 1961 discloses a vane runner fitting wherein the angular relationship between the vane and vane rail is adjustable, such that flat blades or arcuate blades of preformed configuration may be swiveled or tilted relative to the mounting rails.
While such device enables manipulation of a preformed blade somewhat to increase flow efficiency, it still fails to solve the problems inherent in the use of precurved vanes or provide optimal results where nonconventional (non 90.degree.) bends are encountered.